DESCRIPTION (Applicant's abstract) Dr. Suman's long-term career goals and interests are to understand the mechanism(s) by which adaptations occur in the cardiovascular, pulmonary and skeletal muscle systems in response to exercise. Broadly, he foresees himself establishing a scientific investigative career in physiology and using exercise as an interventional tool against functional disability and disease. His immediate career goals involve investigating the adaptations to exercise that occur in severely burned children. Currently, Dr. Suman proposes to continue his research at the University of Texas Medical Branch and Shriners Hospitals for Children, in collaboration with Dr. David N. Herndon, Dr. Robert R. Wolfe and Dr. Daniel L. Traber. Research: The physiological response to a severe burn injury includes a persistent and extensive skeletal muscle catabolism and weakness that leads to a low physical capacity. In non-burn individuals, exercise training induces adaptations that include improvement of cardiovascular (CV) and muscle function. However, whether exercise confers these adaptions in burned children in currently unknown. A better understanding of the adaptations to exercise training is important and relevant in burns, where alterations in cardiovascular and muscle function are major obstacles in the return to physical activities of daily living. The proposed study will test the hypothesis that exercise, in severely burned children, will improve CV and muscle performance by increasing cardiac function, oxygen uptake and utilization, and skeletal muscle mass. Specific Aim 1 will assess whether decreases in CV and skeletal muscle function in severely burned children are due to compromised cardiac performance and skeletal muscle oxidative function and decreased concentration of myosin heavy chain. Specific Aim 2 will assess whether the compromised level of CV and muscle function will be improved with exercise training. Specific Aim 3 will assess whether administration of an anabolic agent (oxandrolone) to burned children will further enhance the effects of exercise on CV and skeletal muscle functional capacity. We expect these Specific Aims to serve as a springboard for future studies in the treatment and long-term rehabilitation of burned children.